Forming cast-in-place concrete incasements of previously driven piles



Nov. 15, 1949 1. H. THORNLEY ET Al. 2,488,073

FORMING CAST-N-PLACE CONCRETE INCASEMENTS 4 OF PREVIOUSLY DRIVEN PILESFiled sept. 15, 1947 3 sheets-sheet 1 24* [i il' Y IIIHIHIII A.

Nov. l5, 1949 J. H. THoRNLl-:Y ET AL 2,488,073

FORMING CAST-IN-PLACE CONCRETE INCASEMENTS OF PREVIOUSLY DRIVEN PILES 3Sheets-Sheet 2 Filed Sept. l5, 1947 IN VEN TORS.

Y NOV 15, 1949 J. H. THORNLEY ET AL 2,488,073

' FORMING CAST-IN-PLACE CONCRETE INCASEMENTS OF PREVIOUSLY DRIVEN PILESFiled Sept. 15, 1947 3 Sheets-Sheet 5 IN VEN TORS Jasep/z/YZ/zorPatented Nov. 15, 1949 UNITED STATES ATENT OFFICE FORMINGv CAST-IN-PLACECONCRETE IN- CASEMENTS OF PREVIOUSLY DRIVEN PILES Application September15, 1947, Serial No. 774,006

11 Claims.

The present invention relates to an improved method of and apparatus forforming cast-inplace concrete incasements on previously driven piles.

The invention has been devised primarily for forming cast-in-placeconcrete incasements over previously driven structural steel piles ofH-beam section, I-beam section or other desired structural shape.However, as We shall hereinafter describe, the invention is alsoapplicable to other types of previously driven piles.

In constructing foundations for buildings, bridges and the like, thereare many situations where structural steel piles afford distinctadvantages over the use of other types of foundation columns. Forexample, structural steel piles have a very high load-bearing value whenextended down to bed-rock, or hardpan or like firm bearing material.These structural steel piles also have the ability to carry high tensileloads as well as compression loads.

The mechanical driving ofthe structural steel piles down to their fullbearing depth by the use of a pile driver or the like affords oneexpeditious manner of sinking these structural steel piles because itavoids the expense and hazard of digging out holes by manual labor.

It is desirable that the driven pile be protected against rusting,electrolysis or otherv corrosion occurring in the ground. I-Ieretofore,it has been attempted to provide such protection by merely painting thepiles or `coating them with some protective material applied in liquidform. I-Iowever, the extreme abrasion encountered by such piles in beingdriven downthrough loose rock, gravel, sand and the like is practicallycertain to scratch a considerable part of this thin coating olf thepile. Consideration has also been given to incasing the pile in aconcrete sheath before driving. However, the above described mechanicaldriving of these structural steel piles usually makes it impracticableto encase the pile in concrete before driving because the heavy blows ofthe pile driving hammer are almost certain to shatter the concrete.

The fundamental object of our invention is to provide an improved methodof and apparatus for forming a cast-in-place incasement over astructural steel pile after the latter has been driven into the groundby a pile driving hammer or the like. By being cast-in-place after thecompletion of the driving operation this concrete incasement does notreceive the driving blows of' the pile driving hammer. Our improvedapparatus comprises a tubular core and casing as-vr sembly which isdriven down over the previously driven pile, the core having anapertured closure head at its lower end whichis adapted to have arelatively snug sliding fit down over the pile, and the casing having arelatively snug sliding fit down over this closure head. The core andcasing assembly are adapted to drive the soil away from around thepreviously driven pile, and to define a surrounding space between thepile and the interior of the casing for receiving the concrete whichforms the cast-in-place incasement.

Another object or feature of the invention is the use of a small batchof concrete or like loose material which is driven down into the groundalong with the core and casing assembly, this batch of concrete beingconfined within the lower end of the casing in advance of the aperturedclosure head of the core, where it functions to seal off the core andcasing assembly against the entrance of dirt as the core and casingassembly are driven down over the previously driven pile. This batch ofconcrete also functions as a scratching and scouring medium for cleaningthe dirt ofi the sides of the structural steel pile as the core andcasing assembly are driven down over the pile, so that the subsequentlypoured charge of concrete can bond directly to the cleaned surfaces ofthe structural steel column. In addition, this plug-like batch ofconcrete which is carried in the lower end of the core and casingassembly serves as a temporary sealing plug for temporarily sealing thelower end of the casing around the structural steel pile while the coreis being withdrawn from the casing after driving and while the mainbatch of concrete is being poured into the surrounding space between thestructural steel pile and the casing for forml ing the cast-in-placeincasement.y

Other objects, features and advantages of the invention will be apparentfrom the following detail description of two preferred embodimentsthereof. In the accompanying drawings illustrating such embodiments:

Figure l is a fragmentary side elevational View of the casing part ofthe core and casing assembly adapted to drive piles of H-beam section;

Figure 2 is a transverse sectional view of this casing;

Figure 3 is a fragmentary side elevational View of the core part of thecore and casing assembly;

` Figure 4 is a transverse sectional View of the core taken on the planeof the line 1 -4V of Figure 3 showing the H-shaped aperture in theclosure plate at the bottom end of the core;

Figure 5 is a fragmentary side View showing the rst step in theoperation' of engaging the core and casing assembly over the upper endof the previously driven steel pile, showing the scouring batch ofconcrete interposed between the lower end of the core and casingassemb-ly and the upper end of the pile;

Figure 6 is a transverse sectional view taken approximately on the planeof the line 6 5 of Figure showing the engagement of the core and casingassembly down over the structural steel pile;

Figure 7 shows the further step of driving the core and casing assemblydown into the ground around the previously driven pile, with thescouring and plugging batch of concrete driven down in advance of thecore;

Figure 8 illustrates the next step wherein the core is removed while thecasing remains temporarily in the ground to receive the poured batch ofconcrete which is to form the incasement;

Figure 9 shows the next step wherein the casing is removed while theconcrete incasement remains in place surrounding the previously drivenDile;

Figure 10 is a transverse sectional view of the incased pile at thecompletion of the above operations, and

Figures 1l, 12, 13 and 14 are views similar to Figures l, 2, 3 and 4showing a modified construction adapted for use in connection withcylindrical piles.

.The casing and core assembly shown in Figures 1, 2, 3 and 4 comprisesthe outer casing designated 20 and the inner core designated 2|. In itspreferred form for use with piles of H-beam section, the casing 20 ispreferably constructed of two inwardly facing channels 22 joined bycross-plates 23 suitably welded, either to the outer sides or the innersides of the channel flanges 22. A heavy driving head or collar 24 issecured around the outer side of the casing at its upper end to receivedriving blows from the pile driving hammer, and also to facilitateconnection with a hoisting tackle when the casing is to be pulled up outof the ground.

The core part of this assembly comprises two longitudinally extendingT-bars 26 disposed back to back in spaced relation to dene a guideway 21therebetween, asclearly shown in Figure 4. At the upper end of the core2| these two T-bars are welded to the underside of a solid driving head28. This driving head receives the driving blows of the pile drivinghammer in the operation of sinking the core and casing assembly aroundthe previously driven pile. At the lower end of the core structure thetwo T-bars 26 are welded to an apertured closure plate 29. This closureplate is formed with an H-shaped opening 3| cut entirely down throughthe plate, this H-shaped opening being of the proper proportions to fitdown over the H-shaped section of the previously driven pile. Aclearance of approximately one quarter of an inch or so is desirablebetween the H-shaped slot and the adjacent surfaces of the H-beam pileso as to accommodate irregularities in the surface of the pile and alsothe rough working conditions characteristic of operations in the eld.The perimeter of this closure plate 29 has approxi-v mately the sameworking clearance within the inside surfaces of the casing 210.

The core structure 2| is approximately a foot or so shorter in lengththan the casing 20, so that when the core is assembled within the casingwith the top driving plate 28 of the core resting on the top drivingring 24 of the casing the lower end of the core will be spaced upwardlyfrom the lower end of the casing. This defines a pocket or cavity Withinthe lower end of the core and casing as- 4 sembly adapted to receive thescouring and plugging batch of concrete, said pocket or cavity beingindicated at 34 in Figure 5. This pocket or cavity may be of any desiredvertical depth.

Referring now to Figure 5 illustrating a first step in the typical useof our core and casing assembly, the previously driven pile of H-beamsection is indicated at 35, this pile having been driven to the desireddepth with a portion of its upper end projecting above the ground lineor grade level. A shallow excavation 36 is formed in the ground aroundthe upper end of the previously driven pile, and into this excavation orhole is placed a charge of concrete 31 which functions as the scouringand sealing plug to be carried down with the core and casing assembly.The upper end of the H-beam pile 35 projects slightly above this batchof concrete 31. The core and casing assembly is then lowered down overthe upper end of the pile, and the core is lined up to have the H-shapedopening 3| slide down over the H-beam 35. Thereupon, the core and casingare lowered So that the core closure plate 29 slides down over theH-beam pile 35 and so that the casing 2 moves down over the upperportion of the batch of concrete 31, whereby the cavity 34 created inthe lower end of the casing 20, below the closure plate 29, confines theupper part of the batch of concrete 31, as clearly shown in Figure 5. Inthis position of the parts, the top driving head 28 on the core isresting upon the top driving ring 24 of the casing. The core and casingassembly is now driven downwardly by blows from the pile driving hammer.In the initial downward movement of the lower edge of the casing 2|!into the batch of concrete 31, a substantial part of this batch isforced upwardly into the cavity 34 for tightly compacting the concretewithin said cavity. This heavy pressure exerted on theconcrete 31 forcesit into the aforementioned clearance areas which are defined between theedges of the H-shaped opening 3| and the side surfaces of the H-beam 35.The batch of concrete 31 is preferably mixed so that it will besuiciently stiff or coarse to substantially restrict its flow throughthese relatively small clearance areas. Some of this concrete may workupwardly through these clearance areas within the H- shaped opening 3|,but in so doing this concrete will exert a vigorous scraping or scouringaction on the adjacent surfaces of the H-beam pile 35 for cleaning thesesurfaces. The batch of concrete 31 is suiciently large so that thisbatch does not become depleted to any great extent by ejection orextrusion up through the clearance areas while the core and casingassembly is being driven down over the pile to the desired depth.

Figure '1 illustrates how a plug 31 of concrete is carried down from thebatch 31 conned within the cavity 34 of the core and casing assembly.This plug 31 receives the full pressure of the driving blows exerted onthe core and casing assembly, and functions as a driving and sealingplug for penetrating the soil and for sealing the lower end of the coreand casing assembly against soil, sand, rocks, gravel or water tendingto work upwardly past the closure head 29 into the casing area 39 abovethis closure head. The concrete performs such sealing function aroundthe perimeter of the closure head 29 as well as in the H-shaped opening3|. In addition, this concrete plug 31 performs a very vigorous scouringor abrasive action against the surfaces of the H-beam pile 35 by reasonof the extreme pressure of the concrete against the surfaces of the zpile. Hence, all of theV surfaces of the pile are cleaned thoroughly sothat the later batch of concrete which is dumped into the space 39 canestablish effective bonding with the surfaces of the pile to form awatertight cast-in-place incasement around the pile. In the operation ofdriving the core and casing assembly down over the H-beam pile, the coreand casing assembly is accurately guided with respect to the pile byreason of the guiding function of the T-bars 26 of the core structure(Figure 6). The guiding contact of the H-beam web against the opposingsurfaces of the T-bars establishes the guided relation in one plane, andthe engagement of the H-beam flanges against the edges of thecrossflanges of the T-bars establishes the guided relation in the otherplane.

The core and casing assembly may be driven down to the whole depth ofthe pile to form a concrete incasement for the entire length of thepile, or the core and casing assembly may be driven down to someintermediate depth if incasing the entire length of the pile is notfeasible or not advantageous. It is not uncommon for these structuralsteel piles to be driven to depths of 100 feet or more, and if it isdesired to incase the entire length of the pile in concrete it will beseen that the core and casing assembly must be of substantiallycorresponding length. In operations of this magnitude the pile and thecore and casing assembly usually consists of two or more sections whichare secured together successively as they are driven down into theground. Figure 8 illustrates the core and casing assembly as having beendriven to a depth short of the lower end of the pile; as for example insituations Where the lower end of the pile is socketed in bed rock,hardpan or other firm bearing material. When the downward driving of thecore and casing assembly is discontinued, the plug 31 of concreteremains confined within the cavity portion 34 of the casing to functionas a closure plug or hard packed seal to prevent the entrance of mud orwater up around the pile into the space 39 within the casing. The corestructure 2l is now lifted up entirely out of the casing, the concreteplug 3T continuing to maintain a hard packed seal in the lower end ofthe casing notwithstanding the removal of the core structure. The casingis then filled with a large charge of concrete 40 which completely iillsthe space 3S and establishes intimate bonding with the cleaned surfacesof the pile. This charge of concrete 40 is preferably a soft workablemix which will completely fill the space 3d in intimate contact with theH-beam pile, whereby to avoid any bridging or cavities and insure thatthe surfaces of the H-beam are effectively sealed at all points againstwater, electrolysis or other corrosion.

The nal operation is that of removing the casing structure 2G whilemaintaining the concrete incasement 4D in r'rn pressure engagementagainst'the H-beam pile. YThis casing removal operation'isdiagrammatically illustrated in Figure 9. In the performance of suchoperation, the core structure 2l is reinserted into the casing With theapertured closure plate 29 sliding down over the H-beam. This closureplate 29 isA weight of the core structure 2l and also the weight of thepile driving hammer upon this charge of concrete 40 while pulling thecasing 2B up out-of the ground. This may be desirable under someconditions to prevent any possibility of upward displacement orseparation of the plastic sheath of wet concrete 40. The finishedcast-in-place concrete incasement is illustrated in Figure 10. Theconcrete sheath has the sectionaly outline defined by the shape of thecasing structure 29, and completely incases all parts of the H-beampile. The casing structure '2,0 is shown as being of rectangularcross-section; but it will be understood that this casing might be ofcir-- cular cross-section, in which case the upper and lower heads 28and 29 of the core structure would also be of circular formation.

Figures 11, 12, 13 and 14 mostrate a modified construction of core andcasing assembly for use in conjunction with cylindrical piles. Thesecylindrical piles may be pipe section piles, wood` piles or evenpre-cast concrete piles, which latter piles might have developed cracks,spalling or damage, thereby making it desirable to form a cast-in-placeconcrete incasement around such pre-cast concrete piles. In thismodified construction casing section 20a is a cylindrical seccylindricalexterior of the previously driven pile 35a. The use of this modifiedconstruction of cylindrical core and casing assembly is substan-v tiallythe same as that described above.

The scouring and sealing plug 31 of loose abrasive material, used ineach of the preceding embodiments, is preferably composed of a moder-Vvately stiif concrete mix and is usually satisfactory for substantiallyall normal working conditions, but we also contemplate the use ofgravel, sand, cinders and the like, which may be satisfactory under someworking conditions.

While We have illustrated and described what we regard to be thepreferred embodiments of our invention and the preferredl methods ofcarrying the invention into eiect, nevertheless it will be understoodthat such are merely exemplary and that numerous modifications andrearrangements may be made therein without departing from the essence ofthe invention.

We claim:

1. The method of forming a cast-in-place concrete incasement over apreviously driven pile, Which-'comprises placing a casing over the upperend of the pile, interposing a plug of loose material between the casingand the pile, driving the casing down over the pile with the plug ofloose material moving down bodily with the casing to function as adriving and scouring plug whereby Y to scour the side` surfaces of thepile and to substantially close the lower end of the casing, and thenforming a cast-in-place concrete incasement within the space between thepile and said casing.

2 The method of forming a cast-in-place concrete incasement over apreviously driven pile, which comprises placing a core and casingassembly over the upper end of the pile, said core and casing elementsboth being tubular to receive the pile and said core being shorter todefine a cavity within the lower end of the casing, interposingabatch'of concrete within said cavity between the casing and the pile,driving the core and casing assembly down over the pile with the batchof concrete moving down bodily with the core and casing assembly overthe pile to function as a scouring and sealing plug adapted to scour theside surfaces of the pile and to seal the lower' end of the casingagainstthe entrance of soil and water, then withdrawing the core,forming a castin-place concrete incasement within the space between saidpile and casing, and then withdrawing the casing.

3. The method of forming a cast-in-place concrete incasement on a,previously driven pile which comprises placing an apertured closuremember over the previously driven pile, placing a casing over saidclosure member, said casing being spaced from said pile, sinking saidclosure member` and casing down into the ground around said previouslydriven pile, and introducing concrete into the space between said casingand said pile to form the cast-in-place concrete incasement.

4. The method of forming a cast-in-place concrete incasement on apreviously driven pile which comprises placing an apertured drive memberover the previously driven pile, the aperture in said member having arelatively close sliding fit with the side surfaces of the pile, placinga casing over said drive member, said casing being spaced from saidpile, driving said drive member and casing down into the ground aroundsaid pile, iilling the space between the casing and the pile withconcrete, and then withdrawing said casing.

5. The method of forming a, cast-in-place concrete incasement on apreviously driven pile which comprises placing a core and casingassembly over the upper end of the pile, said core comprising anapertured lower closure plate having a relatively close sliding t withthe pile, said casing being spaced from said pile, driving said core4and casing assembly down into the ground around said pile, withdrawingsaid core, introducing concrete into the casing to form the cast-inplaceconcrete incasement around said pile, and stripping said casing from theconcrete before the concrete sets.

6. The method of forming a cast-in-place concrete incasement of apreviously driven pile which comprises placing a core and casingassembly over the upper end of the pile, said core comprising anapertured lower closure plate having a relatively close sliding fit withthe pile, said casing being spaced from said pile, driving said core andcasing assembly down into the ground around said pile, withdrawing saidcore, introducing a charge of concrete into said casing, placing saidcore back into said casing upon said charge of concrete, and thenstripping said casing from said charge of concrete while said core ispreventing upward displacement of said concrete.

7. The method of forming a cast-in-place concrete incasement on apreviously driven pile which comprises placing an apertured closureplate and a casing over the previously driven pile, introducing a batchof loose abrasive material between the under side of said closure plate.and the pile, driving the closure plate, casing and abrasive materialdown into the ground around said pile, and then introducing concreteinto the casing around the pile.

8. In apparatus for forming a cast-in-place concrete incasement over apreviously driven pile, the combination of a core structure comprisinga' closure head having an aperture therein adapted to have a sliding itdown over said previously driven pile, a stem portion extending upwardlyfrom said closure head, a driving head at the upper end of said stemportion, a casing engaging said core structure with its lower end havinga relatively snug sliding nt over said closure plate, and a driving ringat the upper end of said casing adapted to receive driving blows fromthe driving head of said core structure.

9, In apparatus for forming a cast-in-place concrete incasement over apreviously driven pile of H-beam section, the combination of a corestructure comprising two parallel T-bars in spaced back-to-backrelation, a closure plate secured to the lower ends of said T-bars, saidclosure plate having an H-shaped opening therein which is adapted tohave a relatively snug sliding t down over the H-beam section of thepreviously Vdriven pile, said T-bars being adapted to move downwardly inguided relation on opposite sides of the web of said H-beam section, adriving plate secured to the upper ends of said T-bars, and a casingsurrounding said core structure and having a driving ring at its upperend receiving driving blows from said driving plate, said casing havingits lower end extending down over said closure plate in a relativelysnug sliding fit and projecting beyond said plate to dene a cavity inits lower end in 'advance of said closure plate which is adapted toreceive a batch of concrete or the like to function as a scouring andsealing plug in the casing as the core and casing assembly is drivendown over the H-beam pile.

l0. In apparatus for forming a cast-in-place concrete incasement over apreviously driven pile of substantially circular outer contour, thecombination of a core structure comprising la length of pipe having abore capable of sliding down freely over the pile, a closure platesecured to the lower end of said pipe provided with a circular openinghaving a relatively snug sliding t over the pile, a driving platesecured to the upper end of said pipe, and la cylindrical casingsurrounding said core structure and having a driving ring at its upperend adapted to receive driving blows from the driving plate of said corestructure, the lower end of said casing extending down over said closureplate in a relatively snug sliding fit and projecting beyond said plateto define a cavity in its lower end in advance of said closure platewhich is adapted to receive la batch of concrete or the like to functionas a scouring and sealing plug in the casing as the core and casingassembly is driven down over the pile.

11. The method of incasing a previously sunk pile in a cast-in-placeconcrete incasement, which comprises driving a casing down over the pilein spaced relation thereto, utilizing a plug of concrete or likematerial to substantially close the lower portion of said casing in thedriving operation, and then introducing concrete into the space betweensaid casing and pile.

JOSEPH H. THORNLEY. HOWARD F. CAUDILL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 953,088 Hindes Mar. 29, 19102,200,524 Watt May 14, 1940 2,428,070 Frenkil Sept. 30, 1947

